Artifact analysis of approximate helical cone-beam CT reconstruction algorithms.
Artifact analysis of approximate helical cone-beam CT reconstruction algorithms.
复制标题
近似螺旋锥束CT重建算法的伪影分析。
DOI：
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发表时间：
2001
期刊：
影响因子：
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通讯作者：
J. Timmer
中科院分区：
文献类型：
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作者：
T. Köhler;R. Proksa;C. Bontus;M. Grass;J. Timmer
本文比较了四种近似锥束CT重建算法：以先进的单层反投影(ASSR)为代表的二维近似重建算法、PI算法、PI-斜算法和3-PI算法，它们都使用了合适的三维反投影。对由这些技术产生的图像伪影的详细分析表明，对于标称切片厚度为1.25 mm的16行扫描仪，z方向上的混叠是伪影的主要来源。对于各向同性分辨率为0.5 mm的探测器，我们发现ASSR和PI产生了几乎相同水平的不同类型的伪影，而PI-SLANT不产生这些伪影。结果表明，3-PI方法中冗余数据的使用有效地抑制了两种扫描仪的混叠伪影。
In this paper, four approximate cone-beam CT reconstruction algorithms are compared: Advanced single slice rebinning (ASSR) as a representative of algorithms employing a two dimensional approximation, PI, PI-SLANT, and 3-PI which all use a proper three dimensional back-projection. A detailed analysis of the image artifacts produced by these techniques shows that aliasing in the z-direction is the predominant source of artifacts for a 16-row scanner with 1.25 mm nominal slice thickness. For a detector with isotropic resolution of 0.5 mm, we found that ASSR and PI produce different kinds of artifacts which are almost at the same level, while PI-SLANT produces none of these artifacts. It is shown that the use of redundant data in the 3-PI method suppresses aliasing artifacts efficiently for both scanners.